This invention relates to a method of improving the working properties of liquid systems, e.g. hydraulic and lubrication ones, which are contaminated mainly with solids possessing magnetostrictive properties.
It is well known that reliability and the longevity of both liquid (hydraulic) systems themselves and the machines they take care of (the lubrication systems of engines, compressors and others), in many respects, depend on the working properties of the used liquids.
These properties are determined, among other things, by the presence of solid contaminants in the liquid, the fineness of the latters and the state of their dispersion.
The solid contaminants are products of wear (metal filings, rubber, etc.) and oxidation of both the details (bearings, gears, seals, etc.) and the working fluid itself, or are atmosphere dust.
The solid contaminants are abrasive, cause wear, decrease (in many times) the term of liquid unit service, may wedge (depending on the size of particles) movable details (especially the plunger ones), be the cause of inoperativeness of automatic controls, be the catalysts of oil oxidation and form tarry substances when the metal and the oil are inappropriately selected.
The main known methods of liquid decontamination are the continuous removing of contaminants from the liquid by means of straining, filtering, gravitational displacement, magnetic and centrifugal separation, etc. Independent continuous or periodic purification are employed with full flow or by-pass (5-20% of the flow).
Common to all the known methods of decontamination is the quest for removing all contaminants from the liquid. Being unable to do so, filtration, for example, is assumed to be the most qualified if the size of the filtrating material calibration channel is less than the half of the minimum clearance in the sliding pair. Still being difficult, it does not go beyond the full clearance. Besides, the fine mesh filters may clog and, in some areas, even become a repository for biological growth.
In our previous application "Method of improving the working properties of fluid systems", a simple and practical method has been devised not only for the same purpose (eliminating the harmful effects of contamination) as the known ones, but for improving the liquid working properties too, and even the system components themselves.
According to that method, the fine solid contaminants are not driven-off, but destroyed up to unaffected size by, among other things, cavitation (ultrasonic or hydrodynamic one), and are intentionally retained in the liquid in dispersed state.
It has been shown that in doing so, the solid contaminants are not only neutralized (by their size reduction to unaffecting size, e.g. less than the half minimum clearance in a sliding pair), but converted into useful particles which substantially improve the antifrictional properties of the rubbing components because they fill the cavities of the worn or defective surfaces, smooth and restore the latters, extend the actual contact area, increase heat transfer between the surfaces, reduce pressure between the latters, the influence of microseizure and other undesirable friction effects. Also, the metallic particles, having a relatively large surface, absorb oil oxidation products and increase the electric conductivity of the liquid. Consequently, the electrostatic component of wear and electrostatic electricity accumulation decrease. The latter, also, adds the fire safety. Besides, oil quality is improved in response to the silent discharges (because of the metallic particles). In engines, also, the deposition of carbon and varnish decreases.
Thus, that method allows not only to diminish as it is too rigid requirements to the filtration, but to improve the system as a whole, increase its longevity and improve the antifrictional properties of rubbing components.
In many cases, the solid contaminants are metals possessing the magnetostrictive properties (changing the volume when subjected to an externally applied magnetic field at temperature below the Curie point of the material). This allows to utilize this magnetostrictive effect in order to eliminate some disadvantages of that method.
The latter agitates (by jets or ultrasonics) whole liquid volume. At this, along with the use (destroying the particles), throttling and cavitation damage the liquid and the metallic surfaces it contacts. The damage of the liquid consists of increasing its acid number and chemical activity, of decreasing its viscosity (FIG. 1), discoloration and molecular-structural breaking-down the liquids with viscous additives consisting of long hydrocarbonic chains.